1. Field of the Invention
The present invention relates to a motorized automobile antenna control device in which an antenna is raised or lowered by means of an antenna up down switch.
2. Prior Art
A motorized automobile antenna control device wherein an antenna is raised and lowered by means of an antenna up-down switch has been known conventionally. In the conventional device, when the antenna up-down switch remains depressed, even after the antenna has reached its highest or lowest point, the antenna driving motor is locked and stops. Thus, a large amount of excess current flows to the motor, resulting in burning damage to the motor.
In order to prevent such burning damage, a clutch is often used between the antenna driving motor and the antenna driving mechanism so that the antenna driving mechanism is caused to slip by means of the clutch when the antenna has reached its highest or lowest point.
Alternately, limit switches may also be used. A system which uses limit switches is designed such that the motor current is automatically cut off when the antenna has reached its highest or lowest point and the limit switches are actuated.
However, installation of clutches or limit switches in antenna control devices so as to prevent burning damage, for example, to the motor, makes the device more complex. Furthermore, the antenna is likely to be damaged if the automobile is parked and the antenna is left extended.